This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A trial to determine if the use of subcutaneous (under the skin) proleukin (IL-2) results in higher CD4 cell counts in patients infected with HIV, but having a CD4 count less than 300/mm3. Worldwide, approximately one in every 100 adults aged 15-49 is HIV infected. This is an estimated 33.4 million people living with HIV/AIDS. Even though educational efforts to modify sexual behaviors have resulted in a decline of HIV infection in some locations, the prediction is that as many as 16,000 people will become infected each day. Much progress has been made in understanding the disease and in implementing potent therapeutic interventions. However, these potent antiretroviral drug combinations do not result in viral eradication and cannot guarantee maintenance of viral control. Thus, treatment must be continuously changed. Among patients with apparent virologic control, a "ceiling effect" seems to exist with failure of CD4+ cell counts to rise on an average of more than 100 to 150 cells/mm3, at least during the first two years. CD4 cells are immune cells that fight against infection. It has recently been speculated that proleukin, in combination with potent antiviral therapy may be a useful approach for purging HIV from the latently infected CD4+ cells. Proleukin is an investigational drug. Subjects in this study have participated in a previous IL-2 study and will enter this study as a follow-up. Several studies have shown that an injection of IL-2 under the skin can increase CD4+ cell counts in most subjects. This study will see if IL-2, in combination with anti-HIV drugs, can cut down on serious infections and prolong the lives of these patients. It will also determine the safety of IL-2 over several years.